Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:121141
MIME-Version: 1.0
References: <a9b0d24f-fe59-75af-4b1e-dcd8067482b0@bastelstu.be>
In-Reply-To: <a9b0d24f-fe59-75af-4b1e-dcd8067482b0@bastelstu.be>
Reply-To: Levi Morrison <levi.morrison@datadoghq.com>
Date: Mon, 25 Sep 2023 13:43:44 -0600
Message-ID: <CAAKU0u=owpz5OEPUzKqPWQQEam+9gYqBCCUqnxUBQCvZU00QVw@mail.gmail.com>
To: =?UTF-8?Q?Tim_D=C3=BCsterhus?= <tim@bastelstu.be>
Cc: PHP internals <internals@lists.php.net>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [PHP-DEV] [VOTE] Increasing the default BCrypt cost
From: internals@lists.php.net ("Levi Morrison via internals")

> Please find the following resources for your references:
>
> RFC Text: https://wiki.php.net/rfc/bcrypt_cost_2023
> Discussion Thread: https://externals.io/message/121004
> Feedback by a Hashcat team member on Fediverse:
> https://phpc.social/@tychotithonus@infosec.exchange/111025157601179075

I did a tiny bit of my own research, and could not find any
recommendations more specific than "10 or more" as the cost factor.
Typically, the advice is "use a more modern system like argon2id".

However, I did notice some sites mention that systems ought to check
for a maximum length of 72 bytes when using bcrypt:
https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html#input-limits

As far as I can tell, PHP does not do this check. I am not sure if the
implementation(s) used suffer(s) from the limitation that is the
source of this recommendation. Perhaps someone has time to investigate
this? Anyway, it's "future work."

I have voted for 11, but will not be hurt in any way if 12 wins.